1. Field of the Invention
The present invention relates to an instrument for use in laparoscopic and endothoracic surgery. More specifically, the invention relates to an endoscopic or laparoscopic dissector which has a variable-angle dissecting tip.
2. Related Art
Numerous designs are known for endoscopic dissectors for use in laparoscopic and endothoracic surgery. However, all of the dissectors which are presently commercially available have one feature in common, a fixed dissecting tip. More precisely, the tips which carry the dissecting blades ar fixed in position except to the extent that they ar capable of reciprocatible movement to effect cutting or dissection. In general, the tips in their closed (non-cutting or non-dissecting) position are aligned with the main tube of the dissector lure are slightly bent with respect thereto.
Examples of commercially-available dissectors having fixed tips are the dolphin nose, Maryland, and right angle dissectors. Additional dissectors having fixed tips are shown in U.S. Pat. No. 1,127,948 to Wappler; U.S. Pat. No. 1,150,214 to London; and West German Patent No. 27 37 014 to Wolf.
USSR Patent No. 980,703 discloses a tissue cutting instrument having two cutters 4 and 5 which are activated by rack and pinion drives from finger levers, both for cutting and for rotation 360 degrees about their pivot axis. However, this type of instrument is suitable only for those applications in which cutting is to be achieved by a true scissor action, because rotation for both cutting and pivoting purposes occurs about a single pivot axis. It is not suitable for pivoting of opposable cutting blades such as those disclosed by Wappler.